Ethanol increases superoxide anion production stimulated with 4β‐phorbol 12‐myristate 13‐acetate in human polymorphonuclear leukocytes

Raddassi, Khadir; Murray, John

doi:10.1046/j.1432-1327.2000.01048.x

Cited by 4 publications

(3 citation statements)

References 40 publications

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“…This observation suggests that methyl 9,10-/12,13-DiHOME inhibits superoxide production during activation of the respiratory burst. We noted that the ethanol vehicle alone (at 0.2% v/v) detectably enhanced PMA-induced lucigenindependent chemiluminescence in this assay (data not shown), consistent with previous reports (Raddassi and Murray 2000). Thus, vehicle controls are particularly appropriate when using this assay system.…”

Section: Methyl 910-/1213-dihome Inhibits the Neutrophil Respiratorsupporting

confidence: 91%

Dihydroxyoctadecamonoenoate esters inhibit the neutrophil respiratory burst

Hammock

2007

J Biosci

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The leukotoxins [9(10)-and 12(13)-EpOME] are produced by activated inflammatory leukocytes such as neutrophils. High EpOME levels are observed in disorders such as acute respiratory distress syndrome and in patients with extensive burns. Although the physiological significance of the EpOMEs remains poorly understood, in some systems, the EpOMEs act as a protoxin, with their corresponding epoxide hydrolase metabolites, 9,10-and 12,13-DiHOME, specifically exerting toxicity. Both the EpOMEs and the DiHOMEs were also recently shown to have neutrophil chemotactic activity. We evaluated whether the neutrophil respiratory burst, a surge of oxidant production thought to play an important role in limiting certain bacterial and fungal infections, is modulated by members of the EpOME metabolic pathway. We present evidence that the DiHOMEs suppress the neutrophil respiratory burst by a mechanism distinct from that of respiratory burst inhibitors such as cyclosporin H or lipoxin A4, which inhibit multiple aspects of neutrophil activation.

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Section: Methyl 910-/1213-dihome Inhibits the Neutrophil Respiratorsupporting

confidence: 91%

Dihydroxyoctadecamonoenoate esters inhibit the neutrophil respiratory burst

Hammock

2007

J Biosci

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“…One required step for NADPH oxidase activation is the phosphorylation of p47 phox by PKC, which permits p47 phox to interact with the cytoplasmic tail of membranebound p22 phox and initiate the formation of an active and membrane-bound enzyme complex (17). PMA activates a PKC pathway independent of receptor stimulation (38) and the activated PKC phosphorylates p47 phox to form a functional NADPH oxidase (44). Apocynin, a selective NADPH oxidase inhibitor, impedes the assembly of NADPH oxidase complex (31), and its ability to block O 2 Ϫ ⅐ production is diagnostic of the presence of a functional NADPH oxidase.…”

Section: Discussionmentioning

confidence: 99%

Superoxide anion is elevated in sympathetic neurons in DOCA-salt hypertension via activation of NADPH oxidase

Dai

Chen²,

Kreulen³

2006

American Journal of Physiology-Heart and Circulatory Physiology

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Ϫ ⅐) production is elevated in sympathetic ganglion neurons and in the vasculature of hypertensive animals; however, it is not known what enzymatic pathway(s) are responsible for O 2 Ϫ ⅐ production. To determine the pathway(s) of O 2 Ϫ ⅐ production in sympathetic neurons, we examined the presence of mRNA of NADPH oxidase subunits in sympathetic ganglionic neurons and differentiated PC-12 cells. The mRNAs for NADPH oxidase subunits p47 phox , p22 phox , gp91 phox , and NOX1 were present in sympathetic neurons and PC-12 cells, whereas the NOX4 homologue was present in sympathetic neurons but not PC-12 cells. Freshly dissociated celiac ganglion neurons from normal rats and PC-12 cells produced O 2 Ϫ ⅐ when treated with the PKC activator PMA; O 2 Ϫ ⅐ production increased by 317% and 254%, respectively. The PMA-evoked increases were reduced by pretreatment with the NADPH oxidase inhibitor apocynin. These findings indicate that NADPH oxidase is the primary source of O 2 Ϫ ⅐ in sympathetic ganglion neurons. When celiac ganglia from hypertensive rats were incubated with apocynin, O 2 Ϫ ⅐ levels were reduced to the same levels as normotensive animals, indicating that NADPH oxidase activity accounted for the elevated O 2 Ϫ ⅐ levels in hypertensive animals. To test this latter finding, we compared NADPH oxidase activity in extracts of prevertebral sympathetic ganglia of DOCA-salt hypertensive rats and shamoperated rats. NADPH oxidase activities were 49.9% and 78.6% higher in sympathetic ganglia of DOCA rats compared with normotensive controls when using ␤-NADH and ␤-NADPH as substrates, respectively. Thus elevated O 2 Ϫ ⅐ levels in hypertension may be a result of the increased activity of NADPH oxidase in postganglionic sympathetic neurons. sympathetic ganglia; phorbol ester; reduced nicotinamide adenine dinucleotide phosphate oxidase; hypertension; deoxycorticosterone acetate VASCULAR ENDOTHELIAL CELLS, smooth muscle cells, and fibroblasts generate reactive oxygen species (ROS), such as O 2 Ϫ ⅐ and H 2 O 2 . ROS play critical roles in both normal and pathophysiological states of vascular cells, including the modulation of redox-sensitive signaling pathways and gene expression, or in the pathophysiology of hypertension and atherosclerosis (16,22,26,36). Several models of hypertension are associated with an increase in vascular O 2 Ϫ ⅐ (41, 42), and this increased O 2 Ϫ ⅐ may quench the endogenous vasodilator nitric oxide (NO) to cause a loss of NO bioactivity in the vessel wall and impair the endothelium-dependent vasorelaxation, resulting in hypertension (26). ROS-mediated endothelial dysfunction in ANG II-infused rats (24) and in DOCA-salt hypertensive rats (42) can be reversed by antioxidant enzyme, endothelial NO synthase (34), or superoxide dismutase (26). ROS can also induce the expression of cardiovascular-related genes, such as those for adhesion molecules and vasoactive substances. For example, the cytokine interleukin 1 activates VCAM-1 gene expression through a mechanism that is repressed ϳ90% by the antioxidant...

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“…In a previous study by Matthews et al [ 18 ] it was demonstrated that ascorbate may significantly decrease the amount of ROS produced by healthy neutrophils stimulated by PMA; however ascorbate was not detected in our samples. Ethanol is known to decrease ROS production by neutrophils [ 32 ] and can increase superoxide production during PMA treatment of neutrophils [ 33 ]. In our studies the PMA-mediated respiratory burst was clearly affected by ethanol as shown by the vehicle control.…”

Section: Resultsmentioning

confidence: 99%

Alteration of Neutrophil Reactive Oxygen Species Production by Extracts of Devil’s Claw (Harpagophytum)

Muzila

Rumpunen

Wright

et al. 2016

Oxidative Medicine and Cellular Longevity

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Harpagophytum, Devil's Claw, is a genus of tuberiferous xerophytic plants native to southern Africa. Some of the taxa are appreciated for their medicinal effects and have been traditionally used to relieve symptoms of inflammation. The objectives of this pilot study were to investigate the antioxidant capacity and the content of total phenols, verbascoside, isoverbascoside, and selected iridoids, as well as to investigate the capacity of various Harpagophytum taxa in suppressing respiratory burst in terms of reactive oxygen species produced by human neutrophils challenged with phorbol myristate acetate (PMA), opsonised Staphylococcus aureus, and Fusobacterium nucleatum. Harpagophytum plants were classified into different taxa according to morphology, and DNA analysis was used to confirm the classification. A putative new variety of H. procumbens showed the highest degree of antioxidative capacity. Using PMA, three Harpagophytum taxa showed anti-inflammatory effects with regard to the PBS control. A putative hybrid between H. procumbens and H. zeyheri in contrast showed proinflammatory effect on the response of neutrophils to F. nucleatum in comparison with treatment with vehicle control. Harpagophytum taxa were biochemically very variable and the response in suppressing respiratory burst differed. Further studies with larger number of subjects are needed to corroborate anti-inflammatory effects of different taxa of Harpagophytum.

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Ethanol increases superoxide anion production stimulated with 4β‐phorbol 12‐myristate 13‐acetate in human polymorphonuclear leukocytes

Cited by 4 publications

References 40 publications

Dihydroxyoctadecamonoenoate esters inhibit the neutrophil respiratory burst

Dihydroxyoctadecamonoenoate esters inhibit the neutrophil respiratory burst

Superoxide anion is elevated in sympathetic neurons in DOCA-salt hypertension via activation of NADPH oxidase

Alteration of Neutrophil Reactive Oxygen Species Production by Extracts of Devil’s Claw (Harpagophytum)

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